JPH07111230B2 - Fluid piping joint - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for fluid piping intended for use in semiconductor manufacturing equipment, vacuum equipment, pharmaceutical manufacturing machines, food machinery, and other fields where high sealing performance is required for fluid piping paths. Regarding fittings.

[0002]

2. Description of the Related Art Conventionally, as a fluid pipe joint used in such a field, a gasket is interposed between flanges of pipes to be connected, and both flanges are joined from the outside by a tightening member. What you do is common. Conventional examples are shown in FIGS. 4, 5, and 6, respectively.

In the conventional example shown in FIG. 4, a disk-shaped metal gasket 4 is interposed between ring-shaped convex portions 3 provided on the opposing surfaces of the flanges 2 of both pipes 1 to be connected, and both flanges 2 are connected.
Male and female screw members 5 and 6 are arranged on the outer side of, and the metal gasket 4 is sandwiched by both ring-shaped convex portions 3 by screwing these screw members 5 and 6 and bringing them closer to each other.

In the conventional example shown in FIG. 5, a rubber O-ring 8 is arranged as a gasket in a ring groove 7 provided in the flange 2 of one of the tubular bodies 1, and male and female screws outside the both flanges 2 are arranged. The members 5 and 6 are screwed together and brought close to each other, so that the O-ring 8 is brought into pressure contact with the facing surface of the flange 2 of the other tubular body 1.

In the conventional example shown in FIG. 6, the convex portions 10a on both sides of the rubber gasket 10 are fitted into the ring grooves 9 provided on the facing surfaces of the flanges 2 of the two tubular bodies 1, and both flanges 2
Is clamped from the outside by the clamp band 11.

[0006]

However, in any of these prior art examples, when the gasket is pressed against the facing surface of the flange, the male and female screw members and the clamp band that apply axial pressure to the flange are pressed against the gasket. After that, only the restraining action of restraining the movement is performed, and only the elasticity of the gasket itself serves as the sealing force.

Therefore, if the gasket is permanently deformed or contracted due to the influence of high temperature or chemicals, the sealing force is impaired and the fluid leaks. For example, in the case of the metal gasket 4 of FIG. 4, although the tensile stress of screw tightening acts as a sealing force, if the gasket itself is permanently deformed, the stopper position of the screw part shifts, and as a result the tensile stress due to screw tightening is It is lost and leaks occur. Moreover, it is difficult to reuse the metal gasket once deformed. Also,
In the case of a metal gasket, leakage may occur depending on the degree of tightening torque of the screw part.

Therefore, in view of the above problems, the object of the present invention can be achieved even if the gasket is deformed or contracted to some extent, and the predetermined sealing force can be maintained, and further, it can be achieved only by adding a simple structure. To do so.

[0009]

In the joint for fluid piping according to the present invention, a spring is interposed between the flange of both pipes to be connected and the tightening member, and the flange is tightened in the axial direction through the spring. Let As one form thereof, as shown in FIG. 1, both flanges 21 are provided with a seat portion 24 joined to a side surface of the gasket 22 and a convex portion 25 joined to an outer peripheral surface of the gasket 22, respectively. Holds the gasket 22 and restrains the movement of the gasket 22 in the radial direction in a state where both the convex portions 25 are separated from each other.
Further, outside the both flanges 21, ring-shaped leaf springs 28 are arranged so as to be inclined on the outer circumferences of both tubular bodies 20, respectively, and both spring pressing members 26 that cover the leaf springs 28 are arranged outside thereof. To do. Then, both the spring pressing members 26 are clamped by the clamp members 29, so that the flanges 21 are axially tightened via the leaf springs 28. As another form, as shown in FIG. 2 or 3, both flanges 21 are provided with a seat portion 24 joined to the side surface of the gasket 22 and a convex portion 25 joined to the outer peripheral surface of the gasket 22, respectively. Both the seat portions 24 sandwich the gasket 22 and the two convex portions 2
It is intended to restrain the movement of the gasket 22 in the radial direction in a state where 5 are separated from each other. Further, a ring-shaped leaf spring 28 is arranged on the outer periphery of the tubular body 20 outside the flange 21 in a tilted manner, and the leaf springs 2 are provided outside both flanges 21.
Male and female screw members 31 and 32 for covering 8 are arranged. Then, the screw members 31 and 32 are screwed together and brought close to each other, whereby the leaf spring 28 is pressed against the flange 21 and tightened. If each flange 21 is provided with a ring-shaped groove 23, the portion left on the inner circumference of the groove 23 can be made a seat portion 24 and the portion left on the outer circumference can be made a convex portion 25.

[0010]

In the case of the present invention, the convex portions 25 of the two flanges 21 restrain the movement of the gasket 22 in the radial direction in a state of being separated from each other, and the spring pressing member 26 or the screw member 31.32.
Is applied to both the flanges 21 via the inclined leaf springs 28, and the seat portion 24 of these flanges 21 clamps the gasket 22 while receiving the elasticity of the leaf springs 28. Even if it contracts, the sealing force is maintained by the spring load. Gasket 2
On the other hand, in both flanges 21, the convex portion 25 restrains the movement of the gasket 22 in the radial direction, while the seat portion 24 presses the gasket 22 with an appropriate area to maintain an appropriate sealing property.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. Two tubes 20
A flange 21 is integrally provided at each of the connection ends of
These are symmetrically opposed. Ring-shaped recessed grooves 23 having a V-shaped cross section are provided on the facing surfaces of the flanges 21 in order to securely hold the ring-shaped gaskets 22 therebetween, and the gaskets 22 remain on the inner periphery of the recessed grooves 23. While being sandwiched by the ring-shaped seat portion 24 of the flange 21, the convex portion 25 remaining on the outer periphery of the concave groove 23 restrains the movement in the radial direction.

A cap-shaped spring pressing member 26 covering the flanges 21 is arranged outside each of the flanges 21 with the ferrules 27 thereof symmetrically opposed to each other. Between the two, two leaf springs 28 in a ring shape are overlapped and arranged obliquely, and the leaf springs 28 in each set are covered with the respective spring pressure members 26 together with the flange 21.

A clamp band (clamp member) 29, which is divided into two in the circumferential direction, is fitted on the outer side of the ferrules 27 of both spring pressing members 26. Then, the clamp band 29 is tightened by a screw mechanism (not shown) to bring the two ferrules 27 closer to each other, so that the two spring pressing members 26 simultaneously press the two sets of leaf springs 28 toward the flanges 21. As a result, the gasket 22
Is pressed from both sides via two sets of leaf springs 28. In this case, the leaf spring 28 includes the spring pressing member 26 and the flange 21.
When the ferrules 27 come into contact with each other, they cannot be tightened, and a prescribed spring load is applied to the gasket 22. Both convex portions 25 restrain the movement of the gasket 22 in the radial direction in a state of being separated from each other.

Therefore, the gasket 22 has the flange 21.
Since a prescribed spring load is applied to seal between the two seats 24, even if the gasket 22 is permanently deformed or contracted by heat, chemicals, etc., the spring load is slightly reduced and leakage does not occur. I can't reach it.

In the case of the structure shown in FIG. 1, the material of the gasket 22 may be metal such as stainless steel, resin such as polytetrafluoroethylene, or rubber, the leaf spring 28 is so-called spring steel, and other parts are stainless steel. Is good. In FIG. 1, reference numeral 30 is a retaining ring fixed to the outer periphery of the tubular body 20 in order to prevent the spring pressing members 26 from separating from each other, which may be omitted.

Next, FIG. 2 shows an example of fastening using male and female screw members 31 and 32. In this case, the male and female screw members 31 and 32 are formed in a cap shape to serve also as the spring pressing member in the example of FIG. 1, and only one set of leaf springs 28 is provided between the female screw member 31 and the flange 21 on one side. It is arranged. Then, when the male and female screw members 31 and 32 are screwed together and brought close to each other, the flange 21 on one side is closed by the leaf spring 28.
The flange 21 on the opposite side is directly pressed by the male screw member 32, while being pressed by the female screw member 31 via the. The leaf spring 28 includes a male screw member 32 and a female screw member 3.
It is doubly covered by the screwed portion with 1.

FIG. 3 also shows an example in which the male and female screw members 31 and 32 are used for fastening, but this is slightly different from FIG. That is, in the example of FIG. 2, the leaf spring 28 is doubly covered with the screwed portion of the male screw member 32 and the female screw member 31, but in the example of FIG. Is.

In each of the embodiments shown in FIGS. 1, 2 and 3, the flange 21 is provided with the ring-shaped groove 23, which is used to secure the seat portion 24 for sealing with the gasket 22. It is for convenience and may be omitted. The same applies to the convex portion 25 that restrains the gasket 22.

In order to confirm the effect of the present invention, a prototype having the structure shown in FIG. 1 was made and tested. In this case, the diameter of the tubular body 20 is 1/2 inch, the material of the gasket 22 is stainless steel, the spring load is about 500 kgf when tightened, and water at 10 ° C and steam at 150 ° C are alternately introduced 10 times each, and helium is introduced. The leak amount was measured with a leak detector, but it was below the minimum sensitivity. For the same gasket, 1
The desorption was performed 0 times, and the leak amount was measured each time.
All were below the minimum sensitivity.

When the same experiment was performed on the conventional structure of FIG. 4, although no leak due to the thermal cycle of water and water vapor was detected, a clear leak was detected at the fifth time in the gasket desorption test, and After the second time, the gasket could not be sealed unless a torque equal to or higher than the first tightening torque was applied.

[0021]

As described above, according to the present invention, the tightening force by the spring pressure member or the screw member is applied to both the flanges through the inclined leaf springs, and the flanges are elastically imparted to the gaskets. Even if the gasket is permanently deformed or contracted, the sealing force can be maintained by the spring load to prevent the occurrence of leakage, and it can be realized with a simple structure. Both flanges against the gasket are rigid because the convex part restrains the radial movement of the gasket and the seat part presses the gasket with an appropriate area to maintain an appropriate sealing property. However, the predetermined sealing property can be ensured with high precision. Therefore, the present invention is particularly effective when the gasket is metal or hard resin. In the case where the gasket is particularly hard, ring-shaped concave grooves are provided in each flange, and the portion remaining on the inner circumference of the concave groove is the seat portion and the portion remaining on the outer circumference is the convex portion. In addition, it is possible to improve the manufacturing accuracy of the seat portion, which is an important portion for ensuring the sealing property.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a sectional view of a third embodiment.

FIG. 4 is a sectional view of a conventional example using a metal gasket.

FIG. 5 is a sectional view of a conventional example using an O-ring.

FIG. 6 is a cross-sectional view of a conventional example using a gasket having a convex portion.

[Explanation of symbols]

 20 Tube 21 Flange 22 Gasket 26 Spring Pressing Member 28 Leaf Spring 29 Clamp Band 31 Female Screw Member 32 Male Screw Member

Claims (3)

[Claims] 1. A flange 2 of both pipes 20 to be connected.
In the fluid pipe joint in which the ring-shaped gasket 22 is interposed between the two and the two flanges 21 are tightened and joined from the outside, the gasket 2 is attached to the both flanges 21.
The seat portion 24 joined to the side surface of 2 and the convex portion 25 joined to the outer peripheral surface of the gasket 22 are respectively provided, the both seat portions 24 sandwich the gasket 22, and the radius of the gasket 22 with both convex portions 25 separated from each other. The movement of the pipes 2 is restricted outside the flanges 21.
The ring-shaped leaf springs 28 are arranged so as to be inclined around the outer circumference of 0, and both spring pressure members 26 that cover the leaf springs 28 are arranged outside thereof. A fluid pipe joint characterized in that both flanges 21 are axially tightened via a leaf spring 28 by being clamped by a clamp member 29. 2. Flange 2 of both pipes 20 to be connected
In the fluid pipe joint in which the ring-shaped gasket 22 is interposed between the two and the two flanges 21 are tightened and joined from the outside, the gasket 2 is attached to the both flanges 21.
The seat portion 24 joined to the side surface of 2 and the convex portion 25 joined to the outer peripheral surface of the gasket 22 are respectively provided, the both seat portions 24 sandwich the gasket 22, and the radius of the gasket 22 with both convex portions 25 separated from each other. That the movement in the direction is restrained, the ring-shaped leaf spring 28 is arranged on the outer circumference of the tubular body 20 outside the flange 21, and the leaf spring 28 is covered on the outside of both flanges 21. A male and female screw member 31, 32 is arranged, and the leaf spring 28 is pressed against the flange 21 and tightened by screwing these screw members 31, 32 into close proximity to each other. 3. A flange 23 is provided with a ring-shaped groove 23, the portion remaining on the inner periphery of the groove 23 is a seat portion 24, and the portion remaining on the outer periphery is a protrusion 25. Item 1
Or the joint for fluid piping according to 2.